package com.leyou.item.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.leyou.item.dto.CategoryDTO;
import com.leyou.item.entity.Category;
import com.leyou.item.entity.CategoryBrand;
import com.leyou.item.mapper.CategoryMapper;
import com.leyou.item.service.CategoryBrandService;
import com.leyou.item.service.CategoryService;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.stream.Collectors;


@Service
public class CategoryServiceImpl extends ServiceImpl<CategoryMapper, Category> implements CategoryService {

    private final CategoryBrandService categoryBrandService;

    public CategoryServiceImpl(CategoryBrandService categoryBrandService){
        this.categoryBrandService = categoryBrandService;
    }

    @Override
    public List<CategoryDTO> queryCategoryByBrandId(Long brandId) {

        // 1.根据品牌id，查询中间表，得到中间表对象集合
        List<CategoryBrand> categoryBrands = categoryBrandService.query()
                .eq("brand_id", brandId).list();

        //从中间表对象集合中获取分类id的集合
        List<Long> categoryIds = categoryBrands.stream().map(CategoryBrand::getCategoryId).collect(Collectors.toList());

        //根据分类id集合查询分类集合,并转换为categoryDTO
        return CategoryDTO.convertEntityList(listByIds(categoryIds));

    }
}
